Play with your computer keyboard (rows 1–0, Q–P, A–;, Z–/) or click the hexes. Every chord shape is the same anywhere on the grid — that's the isomorphic magic. Hold Space as a sustain pedal: tap notes one at a time and they stack until you let go — handy for big chords, since most keyboards can only sense a few keys at once (hardware "ghosting", not a bug in the app).